1. Field of the Invention
The present invention relates generally to network-based computer security and more particularly to methods of and systems for authenticating a device for computer network security.
2. Description of the Related Art
Device identification through digital fingerprinting has proven to be invaluable in recent years to such technologies as security and digital rights management. In security, authentication of a person can be restricted to a limited number of previously authorized devices that are recognized by their digital fingerprints. In digital rights management, use of copyrighted or otherwise proprietary subject matter can be similarly restricted to a limited number of previously authorized devices that are recognized by their digital fingerprints.
Digital fingerprints are particularly useful in uniquely identifying computing devices that are historically know as “IBM PC compatible”. Such devices have an open architecture in which various computer components are easily interchangeable with compatible but different components. There are two primary effects of such an open architecture that facilitate device identification through digital fingerprints.
The first facilitating effect is diversity of device components. Since numerous components of IBM PC compatible devices are interchangeable with comparable but different components, generation of a digital fingerprint from data associated with the respective components of the device are more likely to result in a unique digital fingerprint.
The second facilitating effect is discoverability of details of the various components of IBM PC compatible devices. Since the particular combination of components that make up a given device can vary widely and can come from different manufacturers, the components and the operating system of the device cooperate to provide access to detailed information about the components. Such information can include serial numbers, firmware version and revision numbers, model numbers, etc. This detailed information can be used to distinguish identical components from the same manufacturer and therefore improves uniqueness of digital fingerprints of such devices.
Laptop computing devices evolved from desktop computing devices such as IBM PC compatible devices and share much of the architecture of desktop computing devices, albeit in shrunken form. Accordingly, while users are much less likely to replace graphics circuitry in a laptop device and components therefore vary less in laptop devices, laptop devices still provide enough detailed and unique information about the components of the laptop device to ensure uniqueness of digital fingerprints of laptop devices.
However, the world of computing devices is rapidly changing. Smart phones that fit in one's pocket now include processing resources that were state of the art just a few years ago. In addition, smart phones are growing wildly in popularity. Unlike tablet computing devices of a decade ago, which were based on laptop device architectures, tablet devices available today are essentially larger versions of smart phones.
Smart phones are much more homogeneous than older devices. To make smart phones so small, the components of smart phones are much more integrated, including more and more functions within each integrated circuit (IC) chip. For example, while a desktop computing device can include graphics cards and networking cards that are separate from the CPU, smart phones typically have integrated graphics and networking circuitry within the CPU. Furthermore, while desktop and laptop devices typically include hard drives, which are devices rich with unique and detailed information about themselves, smart phones often include non-volatile solid-state memory, such as flash memory, integrated within the CPU or on the same circuit board as the CPU. Flash memory rarely includes information about the flash memory, such as the manufacturer, model number, etc.
Since these components of smart phones are generally tightly integrated and not replaceable, the amount and variety of unique data within a smart phone that can be used to generate a unique digital fingerprint is greatly reduced relative to older device architectures. In addition, since it is not expected that smart phone components will ever be replaced, there is less support for access to detailed information about the components of smart phones even if such information exists.
Accordingly, it is much more difficult to assure that digital fingerprints of smart phones and similar portable personal computing devices such as tablet devices are unique. What is needed is a way to uniquely identify individual devices in large populations of homogeneous devices.